Assuming this wasn’t an accident, from the extent of the outage it seems that the perpetrators wisely chose where to do the cut. Am I correct in that thinking, or could the same results have been achieved if the cut occurred in many other places?

This is otherwise just another reminder that our near total dependence upon centralized technologically based systems is fragile indeed. We have chosen maximum efficiency in system design rather than erring on the side of mitigating risk via decentralized systems. Maximum efficiency may have made sense in the past but not so much anymore.